.... as much money as Bill Gates of Microsoft, I would retire.
A.If I had
B.If I have
C.Unless I had
D.If I had had

If it.... tomorrow, I will not have to water the plants.
A.will rain
B.is raining
C.would rain
D.rains

I.... the same car for more than ten years. I .... about buying a new one.
A.have had / am thinking
B.will have / think
C.had / will think
D.am going to have / was thinking

My best friend and I.... each other for over fifteen years. We still .... together once a week.
A.were knowing / got
B.knew / have got
C.have known / get
D.
had known / are getting

The secretary.... on the report for more than three hours. She hopes she may finish it by the lunch time.
A.is working
B.will be working
C.has been working
D.had been working

Please turn off the stove. The water.... for more than fifteen minutes.
A.is boiling
B.was boiling
C.has been boiling
D.will be boiling

In the 19th century, it.... two or three months to cross North America by covered wagon. The trip.... very rough and often dangerous.
A.took / was
B.
had taken / had been
C.took / had been
D.had taken / was

Listen! Mr. Jones.... the piano. You.... noise.
A.is playing / should not make
B.plays / will not make
C.has played / do not make
D.played / would not make

Right now, Long…. with his friends. They.... the differences between British English and American English.
A.sits / discuss
B.has been sitting / will discuss
C.was sitting / was discussing
D.is sitting / are discussing

- ....free this afternoon?
- No, I.....
- What....? -....
- I.... my dentist.
A.Will you be / will not / have you done / have seen
B.Have you been / have not / will you do / will see
C.Are you / am not / do you do / see
D.Are you / am not / are you doing / am seeing